There are many reasons for steel pipeline leakage, which can be mainly divided into three categories: corrosion perforation, fatigue rupture, and external force damage.
Although corrosion control measures can significantly slow corrosion, they cannot prevent it. When cathodic protection is insufficient, the steel pipeline corrosion process will be slowed down by cathodic protection but will not stop; when cathodic protection is shielded, it will not inhibit steel pipeline corrosion at all. Insufficient cathodic protection means that the protective current provided by the cathodic protection system cannot meet the steel pipeline protection requirements; cathodic protection shielding means that the cathodic protection current is blocked in the flow and cannot reach the predetermined position. When large-area damage, continuous leaks, or overall insulation performance decline occur on the coating, it can easily lead to insufficient cathodic protection. Since such defects can be discovered through inspection, corrosion accidents can generally be avoided through repair. When the coating peels off from the metal of the pipe body, it will have a shielding effect on the cathodic protection system, especially the coating made of organic synthetic materials with high insulation properties. However, it is difficult to detect coating peeling with existing detection technology, so it is easy to cause Leakage from corrosion punctures.
When oil and gas steel pipelines operate under high-pressure conditions for a long time, the mechanical properties of the steel pipeline metal will gradually decay. The micro-cracks existing in the steel pipeline weld itself and caused by stress corrosion will expand. When the cracks develop to a certain extent, sudden steel pipeline failure will occur. Rupture accident, resulting in leakage. For gas steel pipelines, steel pipeline rupture has potentially catastrophic consequences.
External damage mainly includes natural disasters and man-made disasters. Floods, landslides, mudslides, and earthquakes may damage steel pipelines; man-made disasters mainly refer to third-party damage, including unintentional damage caused by various construction projects such as road construction, excavation, etc., as well as drilling holes to steal oil and gas. Deliberate damage caused by criminals has now become a major threat to steel pipeline protection, and in some areas, it is even the cause of damage.
For large sudden steel pipeline leakage accidents such as pipe bursts and fractures, due to the sudden loss of pressure in the steel pipeline, they can generally be discovered in time, but on-site inspection is required to determine the specific location. For small leaks, leak detection technology is required. Leak detection technology includes offline detection and online monitoring.
Offline inspection is an inspection carried out along the steel pipeline regularly or as required. It can be carried out on foot, by car, or by special aircraft for flight inspection. Leaks are discovered by observing the ground surface, instrument detection, or infrared imaging technology. Because detection is not carried out all the time, this method generally cannot detect leaks in time after they occur.
Online monitoring uses a leakage monitoring system specially installed on the steel pipeline to dynamically monitor the steel pipeline, capture the leakage information at the moment of leakage, issue an alarm, and quickly calculate the leakage location through a computer.
Steel pipeline leakage Oil and gas steel pipeline leakage not only causes oil and gas losses but also pollutes the environment and may even cause fires, explosions, and other accidents. Therefore, it is very important to ensure the safe operation of steel pipelines.
Post time: Jan-10-2024